Pilot stabilizer for pot type oil burners



3 Sheets- Sheet 1 6, 1949 B. HAYTER ETAL PILOT STABILIZER FOR POT TYPE OIL BURNERS Filed Jan. 18, 1947 N\ o #5 v Q Q U a o 0 Q 0 o 0 t 0 0 o n w o h o 0 I O Q Q Q 880833800000ooAw eooooooooo0Q. 823383 V :ual

. 6, 1949 B. HAYTER EI'AL PILOT STABILIZER FOR POT TYPE OIL BURNERS Filed Jan. 18, 1947 3 Sheets-Sheet 2 "'ll' l I III Jnvenzwzs I firuce jfa 3 Sheets-Sheet 3 Filed Jan. 18, 1947 1x06225073 ,Erace 156' fer iizorzeeya Patented Dec. 6, 1949 PILOT STABILIZEB FOR POT TYPE OIL BURNERS Bruce Hayter and Milton D. Huston, Santa Fe, N. Mex., assignors, by mesne assignments, to Breesel Burners, Inc" Santa Fe, N. Mex., a corporation of Delaware Appllcatlon January 18, 1947, Serial rim-122,822

1 Claim.

1 4 Our invention relates to an improvement in liquid fuel burners and has for one purpose to provide improved pilot means for maintaining a.

low turn-down or pilot flame.

Another purpose is' to provide an improved pilot housing adapted to maintain a low flame.

Another purpose is to provide means for preventingcarbon deposit at the low fire or pilot stage.

Other purposes will appear from time to time in the course of the specification. The invention is illustrated more or less diagrammatically in the accompanying drawings wherein:

Figure 1 is a vertical, axial section; Figure 2 is a section on the line 2-2 of Figure 1; Figure 3 is a section on the line 33 of Figure 1; Figure 4 is a section on the line 4-4 of Figure 1; Figure 5 is a section on the line 5-5 of-Figure 2; Figure6 is a section on the line 5-45 of Figure 4;

- rotatable knob having a'pointer I1.

Figure 7 is a'horizontal section, similar to Figure 3, illustrating a variant form;

Figure 8- is a perspective view illustrating a variant form;

Figure 9 is a horizontal section illustrating the form of Figure 8; and

Figure 10 is a horizontal section, similar to Figure 9 but on a smaller scale, illustrating another variant form.

.Like' parts are indicated by like numbers throughout the specification and drawings.

Referring to the drawings, I generally indicates an outer drum or housing, which may be cylindrical in form. It may be supported on any suitable legs or supports 2, separated by air inlet spaces 3. 4 indicates a bottom partition having a central air inlet aperture 5. 6 is a supporting ring, angular in section, one flange of which is secured to the inner surface of the drum I, the other flange being eifective to support the belowdescribed burner pot. 1 indicates an upward extension of the housing I, which may constitute an suitable burner or combustion chamber. It

is provided with any suitable flue means, not

The pot side wall 8 is provided for example, a plurality of secondary air inlets I3, 'circumferentially spaced in and about an upper part of the pot side wall ,8, beneath but near the flame ring II]. The secondary inlets I3 are both larger and more closely spaced thanthe primary inlets I2.

We may employ any suitable means for admitting a liquid fuel to the interior of the pot, for vaporization and combustion. We illustrate, for example, a conventional flow valve assembly It which receives liquid fuel from any suitable source, through the inlet duct I5, It is any suitable control means, which maybe a manually The details of the control do not of themselves form part of the present invention and are not herein indicated. It will be understood that by manipulation of the knob IS the rate of flow of liquid fuel through the inlet or supply duct I8 may be varied. It will be noted that the duct I8 is adapted to deliver liquid fuel to the interior of the pot. It may, for example, be threaded into the nut I9 which is secured to the exterior of the pot.

The present invention relates primarily to the provision of means for maintaining proper. combustion conditions at the pilot or. minimum rate of fuel flow through the duct I8 to the interior of the pot. The pot is shown as having a closed and upwardly concave bottom wall 8a. Within the pot, and surrounding the space into which the liquid fuel initially flows, we provide a pilot housing, having inwardly converging side walls 20, 20, shown as generally perpendicular. They are shown as connected by a generally horizontal top wall portion 2| the outer edge of which, 22, abuts against the inner surface of the pot side wall. 23 is a forwardly or inwardly sloping or inclined top wall portion, which also connects the side walls 20. If desired, the top wall thus formed may be divided into two parts, separated as at 24, the upper part, A, constituting a removablelid, while the lower part, B, constitutes a permanent connection between the side walls 20-.

We find it desirable to provide an air supply for the interior of .the pilot housing thus formed, by having it engage'the pot side 'wall I I at a. level above the lowest row of primary air inlets I2. However, We findit preferable to control the air supply by employing a difierent concentration of primary air inlets than is present in a corresponding pot side wall area outside of the pilot piece. For example, we prefer to concentrate the primary air inlets which deliver air to the interior of the pilot piece in two groups, so arranged as to deliver air against 3 or along the inner faces of the side walls 20. With reference to Figure 4, we illustrate, at each side of the interior of the pilot piece, a group of air inlets, generally indicated at 30. We show three inlets in each group, but it will be understood that the size, shape and arrangement of the inlets may be varied. The direction of air delivery from the two groups appears diagrammatically at x and YinFigure 3.

In addition to the inlets 30 we provide an additional row of preferably smaller inlets 3!, which direct air to a space between the pot side wall and the arcuate air distributor 32. It will be noted that the member 32 terminates in a lower edge 33 which is spaced above the bottom wall la of the pot, and which is also spaced 1 inwardly from the inner face of the pot side wall. Thus, a sheet or reasonably continuous flow of air is directed downwardly along the pot side wall and toward and against the pot bottom, throughout the maximum width of the pilot piece.

We illustrate foraminous shield members secured to the lower surfaces of the top or cover members A and B. The member 40, with its terminal lip ll, is removably secured to the lower These jets may be downwardly inclined, by the downward inclination of the inlets 30, as indicated in Figure 6. In practice, the liquid fuel delivered by the duct is is vaporized as it. flows inwardly upon that part of the bottom wall 8a which is within or under the pilot piece. This takes place at the minimum or pilot flow. The air jets X and Y, together with the air inlets ll, supply the necessary air for complete combustion, and an incurving flame burns at the open mouth or inner end of the pilot piece, as at Z in Figure 3.

It will be understood that a wide variety of modifications or variations in size, shape, number and disposition of parts may be made without departing from the spirit of our invention. For example, as shown in Figure 7, side walls 20a may be inwardly bent or curved at their inner edges, as at 20b, in order to accentuate the tendency of the flame to turn or curve inwardly upon itself intermediateportion 53. Aligned with-the interior or each lobe 52 we illustrate a plurality of generally vertically aligned air inlets 54, each group being so formed and positioned as to direct air jets either against or along the inner surfaces of the side walls SI. .It will be understood, 01' course, that the size, shape and arrangement ofthe inlets 54 may be substantially varied, but

preferably they are so located as to deliver air in general accordance with the showing at X and Y of Figure 8.

If desired, and as shown in Figure 10, the air jets may be directed positively against the inner surface of the side walls. Thus, side walls to 4 of Figure are indicated as generally radial, while the two groups of air inlets ll, 82 are nonradial, and are formed, adapted and arranged to direct impinging jets generally as shown in 5 Figure 10.

All forms herein shown have it in common that the major portion of the air supply for pilot combustion is delivered inwardly along or against the inner surfaces of the side walls of the pilot piece. This result may be obtained in a variety of ways. For example, in Figure 3 the side walls converge on a center radially outwardly spaced from the axis or center of the pot. The air inlets deliver generally radial jets. The result is the desired convergence or impingement. The same result is obtained in the form of Figure 10, where the side walls 80 are generally radial, it being understood that the air inlets GI and 82 are tilted both downwardly and laterally, to obtain a proper direction of the jets.

As the rate of flow of liquid fuel is increased, by manipulation of the knob it, more fuel is supplied than can be evaporated and burned within the pilot piece. The excess fuel flows out over the bottom la, and is there evaporated, receiving and mixing with air flowing into the pot through the primary inlets l2. The primary mixture thus formed is completed by the secondary air admitted through the inlets it. At the high flre, flame flows upwardly through the aperture i I of the flame ring ll.

The use and operation of the invention are as follows The present invention provides an improved pilot stabilizer for pot type bln'ners in'which the liquid fuel is admitted to the interior of the pot. The stabilizer surrounds the point of admission of the liquid fuel to the pot.

We flnd it advantageous to so arrange air inlets in the pot side wall'as to deliver jets to the interior of the stabilizer which converge with, or preferably actually impinge against the side walls of the stabilizer. A practical solution is to use two groups of inlets, one group converging with or impinging against each side wall. It is practical, but not necessary, to blank out some or all of the apertures between-the two said groups. This arrangement of groups of impinging jets is shown in all forms of the present application. We find it desirable also to employ some means, such as the distributor 32, for delivering air downwardly along theside wall and toward and across the bottom of the pot.

An advantage of having two separate groups 55 separated, in effect, b a blanked-out space, is

that the two groups of jets cause an inward suction or return circulation into the dead space between the two groups, there beir'i g a pressure differential which causes a return flow of mixed Q air and products'of combustion into the dead space between the two groups .of air inlets.'

It is not necessary, although it may be desirable, that the side walis be straight. Thus, in Figure 7, side walls are illustrated with inwardly- Q5 curved inner edge portions.

We find it desirable to use a heat-reflecting member which may be spaced downwardly slightly from the top wall of the pilot piece. It may, for example, consist of a foraminous screen.

However, 'a thin, solid sheet may be used. In

either event, dead air space or separation provides insulation between the heat reflector and the top wall of the stabilizer or pilot piece. A primary function of the heat reflector is to reflect 15 heat downwardly toward the bottom wall of the the higher fire the pilot space forms part oi the general combustion space of the burner and does not burn as a separate low flame. In eflect, there is so little air delivered to the pilot space at high flre that the pilot puts itself out. At the low fire, or pilot stage, the outside pot is full of air. This air is recirculated back into the pilot or stabilizer space, and supports pilot combustion. But as combustion increases, and the pot approaches higher fire, then the interior of the pot is largely filled with the products oi combustion 4 and the efl'ective recirculation is to put the pilot fire out, as such, although the pot, as a whole, is burning at higher fire. Thus the pilot becomes inoperative when not needed, but returns to operation when needed. I

It will be realized that whereas a practical and operative device is herein described and illustrated, nevertheless many changes in size, shape, number and disposition of parts may be made without departing from the spirit and content or the invention. It is therefore wished that the description and showing herein be taken as in a broad sense illustrative or diagrammatic, rather than as a limitation to the precise showing herein.

We claim:

In combination, in a pot type burner. a burner pot having a bottom wall, and a circumferential side wall with a plurality 0! air inlet apertures therein, means for directing a liquid fuel to the 6 interior of said pot, a pilot stabilizer surrounding the area of delivery of said fuel to the interior of said pot, said stabilizer including side walls and a top wall adapted to define an inner end aperture in communication with the interior of the pot and adapted to define an outer end aperture closed by a portion of the side wall of the pot, the side walls 01 the, pilot stabilizer convering toward said inner end aperture, the portion of said side wall of the pot having air inlet apertures adapted to direct jets along the opposed inner faces of said stabilizer side walls, and a deflector adapted to deflect air downwardly along that part of the portion of the side wall in communication with the interior of the stabilizer, and toward that portion of the pot bottom which is within the stabilizer, said deflector including a sheet spaced inwardly from the inner face of the pot side wall and defining, with the opposed part of the pot side wall, a space in communication with air inlet apertures in said pot side wall.

BRUCE HAYTER. MILTON D. HUSTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED s'ra'ms PATENTS 

